Control apparatus



Dec. 4, 1928.

H. W. WILLIAMS ET AL CONTROL APPARATUS Filed Dec. 3, 1926 Boozer.

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CONTROL APPARATUS.

Application filed December 3, 1926. Serial No. 152,390.

Another object of our invention 'is' to pro.

vide a contact finger-in which all of the may be easily renewed.

A further object of our invention is to providea contact finger of the above-described parts character which is not only simpleand ee-.

nomieal to manuiacture but effective and reliablein operation.

Further objects of our invention will be- ,come apparent trom the following description, when taken in connection with the accompanying drawing, in which Fig. 1 is aview, in side elevation, of a contact finger embodying our invention, one side of the contact-carrying member being cut "away to show the lJOSlillOIl ot' the parts and the Contact tip beingshownljin its initial contact-making position; 7 r

F g12 is asimilar viewota modified iorm of our contact finger, one side of the contactcarrying member being cut away to show the actuating parts thereof and the contacttip being shown in the position it assumes when r the direction ofmovement ofthe other contact member is reversed;

- Fig. 3 is aiview in sideelevation, of another torinof our contact finger and illustrates the contact tip atthe point immediately preceding "interruption of the circuit:

Referring to Fig. 1, a base member or shank 1 hasa contact-carrying melnber'S pivotally mounted thereon for, in turn, pivot-ally carrying a contact tip l. A lever 5 is pivotally mounted on the eontact-carrying member 3' and is adapted-to rest upon the contact tip 1-.

A resilient member or spring 6 is mounted between an upwardly-extending projection 2 on thefbase member 1 and an intermediate point of the lever 5.

The contact-carrying member Sis pivotally mounte'don the base member 1 by means of a pin 7 and is so designedthat an intermediate shonlder Swill rest upon a shoulder 9 of the base member 1 to cause the contact-carrying member to normally extend in straight-line relation with the supporting element la of the base member '1. 'Ehe contact-carrying member 3, in this particular linger, ismade from a piece of stamped steel and is bent to form a U-shaped element or channel memher, the sides of which may be placed outside of the base member 1, while the contact tip 4 may bemounted within the sides thereof.

The contact-tip 4: is made of a relatively hard material, such as steel, with fiat sides which lit in between the side plates of the contact carrying member 3, and, in side elevation, assumes the shape of a triangle, with the base and corners rounded oiif, or the shape of a segment of a disc. A hole is made near the base surface of the contact tip for inserting a pin 10, by means of which it is mounted near the end of: the contact-carryingmember 3.

The lever 5 is pivotally mounted between the side plates of the contact-carrying memher 3, in the central region thereof, by a pin 11, and is adapted to rotate within a limited rangedeterminedby a projection 12 on the inner end of the lever and the base of the contactcarrying member 8. The lever thus rests upon the rounded surface 13 of the contact tip a and limits the degree of .rotative movement of the tip; The resilient member or helical spring6 is placed or mounted between the end of the projection 2 on the base member 1 and a point approximately midway between the pin 11 holding the lever 5 in place and the pointof contact 14 of the lever 5 with the contact tip 4. r

Suitable bosses15 and 16 are provided upon the projection '2 of thebase member 1 and upon the lever 5, respectively, for thepurpose of holding the spring (3 in place. The contact linger, as a whole, may be mounted upon a suitable fingerboard or block (not shown) by means ofscrews or thelike inserted in the holes '17 and 180i the basemember for that purpose. V

In Fig. 2, a contact finger, identical with thatillustrated in Fig. 1, isshown, with the single exception that, instead of the contact tip 1a having a circularbase for making contact with the lever 5, which rests thereon, it has a plain flat surface 14a with rounded corners. .The tendency thereof is to impart a slightly quicker snap action to the contact tip when it is returning to its normal posi- 'tion.

tip and permitting reciprocatory action thereof. The contact tip fitsin an alined groove in the contact-carrying member, as

illustrated. by the dotted line 33, and is provided with a pin 34, extending loosely through member 23 for receiving the blasing spring 80 WlllCll is secured to the upper end v thereof by a cooperating pin 35 and washer 36. The lower. end of spring rests in a depression in the upper side of contact-carrying member 23. Spring 31, corresponding to previously described spring 6, is located between projection 22 and an intermediate point of member 23.

The operation of the contact finger is briefly as follows:

Let itbe assumed that a cooperating con tact surface 19 is provided for our contact finger (such as that shown in Fig. 1, for example and that the surface 19 is moved to a posit-ion in which the contact tip 4 enlt. This action will cause the contact member 4 to rotate in a clockwise direction around the pin 10. In doing so, it will cause the lever- 5, which rests upon the surface of the contact tip 4, to rise and thereby compress the spring 6 which is placed between the projection 2 on the base member 1 and the lever .The direction of the force produced by the spring 6 and the lever 5 will shift along the surface 14 of the contact tip 4 as the tip is made to rotate. The tendency thereof will be to exert a pressure between the cont-act tip and the sliding surface 19, which pressure will causethe contact tip 4 to snap to its normal position very rapidly, when it leaves the sliding surface, and, by doing so, reduce the possible arcing or spar ing between the contact tip 4 and the contact surface 19.

t In case it should be necessary to reverse the direction of motion of the cont-act surface 19 before it has completely, passed under the contact tip 4, the movable contacbcarrying member 3,,being pivoted to the base member 1 and cooperating with the spring (3, pernit-s the contact tip 4 to turn about its point of contact with the contact surface 22, as

shown in Fig. 2, after which the contactwill assume a position withrespect to the sliding surface 19 similar to that taken in its initial contact-making position, but in a reverse dinoted that the contact-making tip itself has the surfaces nearest the spring 6, such as surfaces 13, rounded off to a greater degree than the cooperating surface -mo=re remote from the spring. It will be readily understood that the reason for thisis that the same pressure will be exerted upon the spring 6 by the action of the contact tip 4, througha lesser distanceat point where the contact tip 4 mak s contact with the lever 5, which is nearest to the point where the lever 5 is pivoted to the contact-carrying member.

Vfhiic we have shown our invention m a plurality of preferred forms, it is apparent that further modifications may be made in the arrange nent of the parts ei'nployed without departing from the spirit of our invention. it will be understood that we do not limit our invention to the specific apparatus illustrated, but desire that only such limitations shall be imposed as are indicated in the appended claims.

iVe claim as our invention:

1. A contact finger comprising a base member, a contact-carrying member pivotaily mounted on said base member and carrying a contact tip pivotally mounted thereon, a lever pivotally mounted on said contactcarrying member and resting on said contact tip and a spring adapted to force said lever against said contact tip and urge said contact-carrying member toward its normal position. v t v A control finger of the sliding-contact type comprising a base member having a projecting portion, a contact-carrying member pivotally mounted on said base member and adapted to rotate in a limited are with respectthereto, a contact tip pivotally mounted on said contact-carrying member, a lever pivotallymounted on said contact-carrying member and resting upon saidoontact tip and a spring placed between said projecting portion of the base member and a point near the center of said lever.

8. A contact finger comprising a base memher, a contact-carrying member pivotally mounted on said base member and having a contact tip pivotally mounted thereon, a lever pivotally mounted on said contact-carrying member and resting upon said tip and a resilient member mounted between said lever and a projection on said base member.

4. A contact linger comprising a base member, a contact-carrying member pivotally mountedthereon and having a pivotally mounted. contact tip, a lever pivotally mounted on said contact-carrying member and adapted to turn within a limited range to limit the amount of rotation of said contact tip and a resilient member mounted between said lever and a projectionon said base member. V i

5. A contact finger comprising a base member, a contact-carrying member pivot- 1,ees,es1 8 ally mounted thereon and adapted toirest on a shoulder on said base member in substantially straight-lme relation therewith, a contact tip pivotally mounted on the free end of said contactcarryingmember, a lever pivotally mounted near its fixed end and a resilient member mountedbetween said lever and a projection on said base member.

6. A contact finger comprising a base member, a contact-carrying member pivotally mounted thereon and having a, triangular shaped contact tip provided with a rounded base and corners pivotally mounted thereon near its base, a resilient member mounted between said base member and said contact tip and means adapted to cooperate therewith tor exerting a force on said contact-carrying member to permit a deflection thereof and for'exerting a force on said contact tip tending to maintain it in one relative position and imparting a snap-action movement to return it to said therefrom. V

7. A contact finger comprising a base member and a contact-carrying member pivotally mounted'thereon, a resilient member mounted between a projection on said base member and said contact-carrying member, a triangular shaped contact tip having a position after any deflection rounded base and a cylindrical shaft cen-- trally located therein, said contact-carrying member having a hole near its free end for receiving the shaft on said tip and adapted to permit a limited rotative movement of said ti p,a.groove in said contact-carrying member for holding said tip in alinementwith said member and a helicalspring suitably mounted around the part of said shaft extending above the contact-carrying member and attached thereto to exert a tension for urging said tip to retain a normal position with respect to said contact-carrying member.

8. In a contact finger, in combination a base member, a plurality of pivotally mounted levers carried by the base member, a contact tip pivotally mounted on one of said levers and disposed to be engaged by the other lever, and resilient means interposed between the base men'iber and the contact tip engaging lever, to bias the contact tip to a predetermined position.

9. In a contact finger, in combination a base member, a contact carrying member pivotally secured to the base member, a contact tip pivotally mounted on the contact carrying member, a lever interposed between the base member and the contact tip, and engaging said tip, a resilient member disposed between said lever and said base member, the lever and resilient member being disposed to impart a snapaction to the contact tip to return it to a predetermined position.

In testimony whereof, we have hereunto subscribed our names this 20th day of November, 1926.

HAROLD WVILLIAMS. DOUGLAS G. BOOZER. 

